The following relates generally to wireless communication, and more specifically to size ambiguity reduction and false alarm rate reduction for polar codes.
Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power). Examples of such multiple-access systems include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, and orthogonal frequency division multiple access (OFDMA) systems, (e.g., a Long Term Evolution (LTE) system, or a New Radio (NR) system). A wireless multiple-access communications system may include a number of base stations or access network nodes, each simultaneously supporting communication for multiple communication devices, which may be otherwise known as user equipment (UE).
In LTE systems, a physical downlink shared channel (PDCCH) carries data and signaling information to a UE, including a downlink control information (DCI) message. The DCI message includes information regarding downlink scheduling assignments, uplink resource grants, transmission scheme, uplink power control, hybrid automatic return repeat request (HARQ) information, modulation and coding schemes (MCS) and other information. A DCI message can be UE-specific (dedicated) or cell-specific (common) and placed in different dedicated and common search spaces within the PDCCH depending on a format of the DCI message. A UE attempts to decode the DCI by performing a process known as a blind decode, during which multiple decode attempts are carried out in the search spaces until the DCI message is detected. The different formats may result in the DCI messages being of different sizes, and ambiguity in the size of the DCI message creates challenges for existing implementations during blind decoding.